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cwfg.c revision 1.4.4.1
      1 /* $NetBSD: cwfg.c,v 1.4.4.1 2021/05/08 16:46:43 thorpej Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2020 Jared McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: cwfg.c,v 1.4.4.1 2021/05/08 16:46:43 thorpej Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/systm.h>
     34 #include <sys/kernel.h>
     35 #include <sys/device.h>
     36 #include <sys/conf.h>
     37 #include <sys/bus.h>
     38 #include <sys/kmem.h>
     39 
     40 #include <dev/i2c/i2cvar.h>
     41 
     42 #include <dev/sysmon/sysmonvar.h>
     43 #include <dev/sysmon/sysmon_taskq.h>
     44 
     45 #include <dev/fdt/fdtvar.h>
     46 
     47 #define	VERSION_REG	0x00
     48 #define	VCELL_HI_REG	0x02
     49 #define	 VCELL_HI	__BITS(5,0)
     50 #define	VCELL_LO_REG	0x03
     51 #define	 VCELL_LO	__BITS(7,0)
     52 #define	SOC_HI_REG	0x04
     53 #define	SOC_LO_REG	0x05
     54 #define	RTT_ALRT_HI_REG	0x06
     55 #define	 RTT_ALRT	__BIT(7)
     56 #define	 RTT_HI		__BITS(4,0)
     57 #define	RTT_ALRT_LO_REG	0x07
     58 #define	 RTT_LO		__BITS(7,0)
     59 #define	CONFIG_REG	0x08
     60 #define	 CONFIG_ATHD	__BITS(7,3)
     61 #define	 CONFIG_UFG	__BIT(1)
     62 #define	MODE_REG	0x0a
     63 #define	 MODE_SLEEP	__BITS(7,6)
     64 #define	  MODE_SLEEP_WAKE	0x0
     65 #define	  MODE_SLEEP_SLEEP	0x3
     66 #define	 MODE_QSTRT	__BITS(5,4)
     67 #define	 MODE_POR	__BITS(3,0)
     68 #define	BATINFO_REG(n)	(0x10 + (n))
     69 
     70 #define	VCELL_STEP	312
     71 #define	VCELL_DIV	1024
     72 #define	BATINFO_SIZE	64
     73 #define	RESET_COUNT	30
     74 #define	RESET_DELAY	100000
     75 
     76 enum cwfg_sensor {
     77 	CWFG_SENSOR_VCELL,
     78 	CWFG_SENSOR_SOC,
     79 	CWFG_SENSOR_RTT,
     80 	CWFG_NSENSORS
     81 };
     82 
     83 struct cwfg_softc {
     84 	device_t	sc_dev;
     85 	i2c_tag_t	sc_i2c;
     86 	i2c_addr_t	sc_addr;
     87 	int		sc_phandle;
     88 
     89 	uint8_t		sc_batinfo[BATINFO_SIZE];
     90 
     91 	u_int		sc_alert_level;
     92 	u_int		sc_monitor_interval;
     93 	u_int		sc_design_capacity;
     94 
     95 	struct sysmon_envsys *sc_sme;
     96 
     97 	envsys_data_t	sc_sensor[CWFG_NSENSORS];
     98 };
     99 
    100 #define	CWFG_MONITOR_INTERVAL_DEFAULT	8
    101 #define	CWFG_DESIGN_CAPACITY_DEFAULT	2000
    102 #define	CWFG_ALERT_LEVEL_DEFAULT	0
    103 
    104 static const struct device_compatible_entry compat_data[] = {
    105 	{ .compat = "cellwise,cw201x" },
    106 	DEVICE_COMPAT_EOL
    107 };
    108 
    109 static int
    110 cwfg_lock(struct cwfg_softc *sc)
    111 {
    112 	return iic_acquire_bus(sc->sc_i2c, 0);
    113 }
    114 
    115 static void
    116 cwfg_unlock(struct cwfg_softc *sc)
    117 {
    118 	iic_release_bus(sc->sc_i2c, 0);
    119 }
    120 
    121 static int
    122 cwfg_read(struct cwfg_softc *sc, uint8_t reg, uint8_t *val)
    123 {
    124 	return iic_smbus_read_byte(sc->sc_i2c, sc->sc_addr, reg, val, 0);
    125 }
    126 
    127 static int
    128 cwfg_write(struct cwfg_softc *sc, uint8_t reg, uint8_t val)
    129 {
    130 	return iic_smbus_write_byte(sc->sc_i2c, sc->sc_addr, reg, val, 0);
    131 }
    132 
    133 static void
    134 cwfg_sensor_refresh(struct sysmon_envsys *sme, envsys_data_t *e)
    135 {
    136 	struct cwfg_softc *sc = sme->sme_cookie;
    137 	u_int vcell, rtt, tmp;
    138 	uint8_t val;
    139 	int error, n;
    140 
    141 	e->state = ENVSYS_SINVALID;
    142 
    143 	if ((error = cwfg_lock(sc)) != 0)
    144 		return;
    145 
    146 	switch (e->private) {
    147 	case CWFG_SENSOR_VCELL:
    148 		/* Take the average of three readings */
    149 		vcell = 0;
    150 		for (n = 0; n < 3; n++) {
    151 			if ((error = cwfg_read(sc, VCELL_HI_REG, &val)) != 0)
    152 				goto done;
    153 			tmp = __SHIFTOUT(val, VCELL_HI) << 8;
    154 			if ((error = cwfg_read(sc, VCELL_LO_REG, &val)) != 0)
    155 				goto done;
    156 			tmp |= __SHIFTOUT(val, VCELL_LO);
    157 			vcell += tmp;
    158 		}
    159 		vcell /= 3;
    160 
    161 		e->state = ENVSYS_SVALID;
    162 		e->value_cur = ((vcell * VCELL_STEP) / VCELL_DIV) * 1000;
    163 		break;
    164 
    165 	case CWFG_SENSOR_SOC:
    166 		if ((error = cwfg_read(sc, SOC_HI_REG, &val)) != 0)
    167 			goto done;
    168 
    169 		if (val != 0xff) {
    170 			e->state = ENVSYS_SVALID;
    171 			e->value_cur = val;			/* batt % */
    172 		}
    173 		break;
    174 
    175 	case CWFG_SENSOR_RTT:
    176 		if ((error = cwfg_read(sc, RTT_ALRT_HI_REG, &val)) != 0)
    177 			goto done;
    178 		rtt = __SHIFTOUT(val, RTT_HI) << 8;
    179 		if ((error = cwfg_read(sc, RTT_ALRT_LO_REG, &val)) != 0)
    180 			goto done;
    181 		rtt |= __SHIFTOUT(val, RTT_LO);
    182 
    183 		if (rtt != 0x1fff) {
    184 			e->state = ENVSYS_SVALID;
    185 			e->value_cur = rtt;			/* minutes */
    186 		}
    187 		break;
    188 	}
    189 
    190 done:
    191 	cwfg_unlock(sc);
    192 }
    193 
    194 static void
    195 cwfg_attach_battery(struct cwfg_softc *sc)
    196 {
    197 	envsys_data_t *e;
    198 
    199 	/* Cell voltage */
    200 	e = &sc->sc_sensor[CWFG_SENSOR_VCELL];
    201 	e->private = CWFG_SENSOR_VCELL;
    202 	e->units = ENVSYS_SVOLTS_DC;
    203 	e->state = ENVSYS_SINVALID;
    204 	strlcpy(e->desc, "battery voltage", sizeof(e->desc));
    205 	sysmon_envsys_sensor_attach(sc->sc_sme, e);
    206 
    207 	/* State of charge */
    208 	e = &sc->sc_sensor[CWFG_SENSOR_SOC];
    209 	e->private = CWFG_SENSOR_SOC;
    210 	e->units = ENVSYS_INTEGER;
    211 	e->state = ENVSYS_SINVALID;
    212 	e->flags = ENVSYS_FPERCENT;
    213 	strlcpy(e->desc, "battery percent", sizeof(e->desc));
    214 	sysmon_envsys_sensor_attach(sc->sc_sme, e);
    215 
    216 	/* Remaining run time */
    217 	e = &sc->sc_sensor[CWFG_SENSOR_RTT];
    218 	e->private = CWFG_SENSOR_RTT;
    219 	e->units = ENVSYS_INTEGER;
    220 	e->state = ENVSYS_SINVALID;
    221 	strlcpy(e->desc, "battery remaining minutes", sizeof(e->desc));
    222 	sysmon_envsys_sensor_attach(sc->sc_sme, e);
    223 }
    224 
    225 static void
    226 cwfg_attach_sensors(struct cwfg_softc *sc)
    227 {
    228 	sc->sc_sme = sysmon_envsys_create();
    229 	sc->sc_sme->sme_name = device_xname(sc->sc_dev);
    230 	sc->sc_sme->sme_cookie = sc;
    231 	sc->sc_sme->sme_refresh = cwfg_sensor_refresh;
    232 	sc->sc_sme->sme_events_timeout = sc->sc_monitor_interval;
    233 	sc->sc_sme->sme_class = SME_CLASS_BATTERY;
    234 	sc->sc_sme->sme_flags = SME_INIT_REFRESH;
    235 
    236 	cwfg_attach_battery(sc);
    237 
    238 	sysmon_envsys_register(sc->sc_sme);
    239 }
    240 
    241 static int
    242 cwfg_set_config(struct cwfg_softc *sc)
    243 {
    244 	u_int alert_level;
    245 	bool need_update;
    246 	uint8_t config, mode, val;
    247 	int error, n;
    248 
    249 	/* Read current config */
    250 	if ((error = cwfg_read(sc, CONFIG_REG, &config)) != 0)
    251 		return error;
    252 
    253 	/* Update alert level, if necessary */
    254 	alert_level = __SHIFTOUT(config, CONFIG_ATHD);
    255 	if (alert_level != sc->sc_alert_level) {
    256 		config &= ~CONFIG_ATHD;
    257 		config |= __SHIFTIN(sc->sc_alert_level, CONFIG_ATHD);
    258 		if ((error = cwfg_write(sc, CONFIG_REG, config)) != 0)
    259 			return error;
    260 	}
    261 
    262 	/* Re-read current config */
    263 	if ((error = cwfg_read(sc, CONFIG_REG, &config)) != 0)
    264 		return error;
    265 
    266 	/*
    267 	 * We need to upload a battery profile if either the UFG flag
    268 	 * is unset, or the current battery profile differs from the
    269 	 * one in the DT.
    270 	 */
    271 	need_update = (config & CONFIG_UFG) == 0;
    272 	if (need_update == false) {
    273 		for (n = 0; n < BATINFO_SIZE; n++) {
    274 			if ((error = cwfg_read(sc, BATINFO_REG(n), &val)) != 0)
    275 				return error;
    276 			if (sc->sc_batinfo[n] != val) {
    277 				need_update = true;
    278 				break;
    279 			}
    280 		}
    281 	}
    282 	if (need_update == false)
    283 		return 0;
    284 
    285 	aprint_verbose_dev(sc->sc_dev, "updating battery profile\n");
    286 
    287 	/* Update battery profile */
    288 	for (n = 0; n < BATINFO_SIZE; n++) {
    289 		val = sc->sc_batinfo[n];
    290 		if ((error = cwfg_write(sc, BATINFO_REG(n), val)) != 0)
    291 			return error;
    292 	}
    293 
    294 	/* Set UFG flag to switch to new profile */
    295 	if ((error = cwfg_read(sc, CONFIG_REG, &config)) != 0)
    296 		return error;
    297 	config |= CONFIG_UFG;
    298 	if ((error = cwfg_write(sc, CONFIG_REG, config)) != 0)
    299 		return error;
    300 
    301 	/* Restart the IC with new profile */
    302 	if ((error = cwfg_read(sc, MODE_REG, &mode)) != 0)
    303 		return error;
    304 	mode |= MODE_POR;
    305 	if ((error = cwfg_write(sc, MODE_REG, mode)) != 0)
    306 		return error;
    307 	delay(20000);
    308 	mode &= ~MODE_POR;
    309 	if ((error = cwfg_write(sc, MODE_REG, mode)) != 0)
    310 		return error;
    311 
    312 	return error;
    313 }
    314 
    315 static int
    316 cwfg_init(struct cwfg_softc *sc)
    317 {
    318 	uint8_t mode, soc;
    319 	int error, retry;
    320 
    321 	cwfg_lock(sc);
    322 
    323 	/* If the device is in sleep mode, wake it up */
    324 	if ((error = cwfg_read(sc, MODE_REG, &mode)) != 0)
    325 		goto done;
    326 	if (__SHIFTOUT(mode, MODE_SLEEP) == MODE_SLEEP_SLEEP) {
    327 		mode &= ~MODE_SLEEP;
    328 		mode |= __SHIFTIN(MODE_SLEEP_WAKE, MODE_SLEEP);
    329 		if ((error = cwfg_write(sc, MODE_REG, mode)) != 0)
    330 			goto done;
    331 	}
    332 
    333 	/* Load battery profile */
    334 	if ((error = cwfg_set_config(sc)) != 0)
    335 		goto done;
    336 
    337 	/* Wait for chip to become ready */
    338 	for (retry = RESET_COUNT; retry > 0; retry--) {
    339 		if ((error = cwfg_read(sc, SOC_HI_REG, &soc)) != 0)
    340 			goto done;
    341 		if (soc != 0xff)
    342 			break;
    343 		delay(RESET_DELAY);
    344 	}
    345 	if (retry == 0) {
    346 		aprint_error_dev(sc->sc_dev,
    347 		    "WARNING: timeout waiting for chip ready\n");
    348 	}
    349 
    350 done:
    351 	cwfg_unlock(sc);
    352 
    353 	return error;
    354 }
    355 
    356 static int
    357 cwfg_parse_resources(struct cwfg_softc *sc)
    358 {
    359 	const u_int *batinfo;
    360 	int len = 0, n;
    361 
    362 	batinfo = fdtbus_get_prop(sc->sc_phandle,
    363 	    "cellwise,bat-config-info", &len);
    364 	switch (len) {
    365 	case BATINFO_SIZE:
    366 		memcpy(sc->sc_batinfo, batinfo, BATINFO_SIZE);
    367 		break;
    368 	case BATINFO_SIZE * 4:
    369 		for (n = 0; n < BATINFO_SIZE; n++)
    370 			sc->sc_batinfo[n] = be32toh(batinfo[n]);
    371 		break;
    372 	default:
    373 		aprint_error_dev(sc->sc_dev,
    374 		    "missing or invalid battery info\n");
    375 		return EINVAL;
    376 	}
    377 
    378 	if (of_getprop_uint32(sc->sc_phandle,
    379 	    "cellwise,monitor-interval", &sc->sc_monitor_interval) != 0) {
    380 		sc->sc_monitor_interval = CWFG_MONITOR_INTERVAL_DEFAULT;
    381 	}
    382 
    383 	if (of_getprop_uint32(sc->sc_phandle,
    384 	    "cellwise,design-capacity", &sc->sc_design_capacity) != 0) {
    385 		sc->sc_design_capacity = CWFG_DESIGN_CAPACITY_DEFAULT;
    386 	}
    387 
    388 	if (of_getprop_uint32(sc->sc_phandle,
    389 	    "cellwise,alert-level", &sc->sc_alert_level) != 0) {
    390 		sc->sc_alert_level = CWFG_ALERT_LEVEL_DEFAULT;
    391 	}
    392 
    393 	return 0;
    394 }
    395 
    396 static int
    397 cwfg_match(device_t parent, cfdata_t match, void *aux)
    398 {
    399 	struct i2c_attach_args *ia = aux;
    400 	int match_result;
    401 
    402 	if (iic_use_direct_match(ia, match, compat_data, &match_result))
    403 		return match_result;
    404 
    405 	/* This device is direct-config only. */
    406 
    407 	return 0;
    408 }
    409 
    410 static void
    411 cwfg_attach(device_t parent, device_t self, void *aux)
    412 {
    413 	struct cwfg_softc *sc = device_private(self);
    414 	struct i2c_attach_args *ia = aux;
    415 	uint8_t ver;
    416 	int error;
    417 
    418 	sc->sc_dev = self;
    419 	sc->sc_i2c = ia->ia_tag;
    420 	sc->sc_addr = ia->ia_addr;
    421 	sc->sc_phandle = devhandle_to_of(device_handle(self));
    422 
    423 	cwfg_lock(sc);
    424 	error = cwfg_read(sc, VERSION_REG, &ver);
    425 	cwfg_unlock(sc);
    426 
    427 	if (error != 0) {
    428 		aprint_error(": device not responding, error = %d\n", error);
    429 		return;
    430 	}
    431 
    432 	aprint_naive("\n");
    433 	aprint_normal(": CellWise CW2015 Fuel Gauge IC (ver. 0x%02x)\n", ver);
    434 
    435 	if (cwfg_parse_resources(sc) != 0) {
    436 		aprint_error_dev(self, "failed to parse resources\n");
    437 		return;
    438 	}
    439 
    440 	if (cwfg_init(sc) != 0) {
    441 		aprint_error_dev(self, "failed to initialize device\n");
    442 		return;
    443 	}
    444 
    445 	cwfg_attach_sensors(sc);
    446 }
    447 
    448 CFATTACH_DECL_NEW(cwfg, sizeof(struct cwfg_softc),
    449     cwfg_match, cwfg_attach, NULL, NULL);
    450